diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 165 |
1 files changed, 91 insertions, 74 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index bf38fde667e9..521ce031ee35 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -8815,112 +8815,129 @@ static void dev_xdp_uninstall(struct net_device *dev) } } -/** - * dev_change_xdp_fd - set or clear a bpf program for a device rx path - * @dev: device - * @extack: netlink extended ack - * @fd: new program fd or negative value to clear - * @expected_fd: old program fd that userspace expects to replace or clear - * @flags: xdp-related flags - * - * Set or clear a bpf program for a device - */ -int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, - int fd, int expected_fd, u32 flags) +static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack, + struct bpf_prog *new_prog, struct bpf_prog *old_prog, + u32 flags) { - const struct net_device_ops *ops = dev->netdev_ops; - enum bpf_xdp_mode mode = dev_xdp_mode(flags); - bool offload = mode == XDP_MODE_HW; - u32 prog_id, expected_id = 0; - struct bpf_prog *prog; + struct bpf_prog *cur_prog; + enum bpf_xdp_mode mode; bpf_op_t bpf_op; int err; ASSERT_RTNL(); - bpf_op = dev_xdp_bpf_op(dev, mode); - if (!bpf_op) { - NL_SET_ERR_MSG(extack, "underlying driver does not support XDP in native mode"); - return -EOPNOTSUPP; + /* just one XDP mode bit should be set, zero defaults to SKB mode */ + if (hweight32(flags & XDP_FLAGS_MODES) > 1) { + NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set"); + return -EINVAL; + } + /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */ + if (old_prog && !(flags & XDP_FLAGS_REPLACE)) { + NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified"); + return -EINVAL; } - prog_id = dev_xdp_prog_id(dev, mode); - if (flags & XDP_FLAGS_REPLACE) { - if (expected_fd >= 0) { - prog = bpf_prog_get_type_dev(expected_fd, - BPF_PROG_TYPE_XDP, - bpf_op == ops->ndo_bpf); - if (IS_ERR(prog)) - return PTR_ERR(prog); - expected_id = prog->aux->id; - bpf_prog_put(prog); - } - - if (prog_id != expected_id) { - NL_SET_ERR_MSG(extack, "Active program does not match expected"); - return -EEXIST; - } + mode = dev_xdp_mode(flags); + cur_prog = dev_xdp_prog(dev, mode); + if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) { + NL_SET_ERR_MSG(extack, "Active program does not match expected"); + return -EEXIST; } - if (fd >= 0) { + if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) { + NL_SET_ERR_MSG(extack, "XDP program already attached"); + return -EBUSY; + } + + if (new_prog) { + bool offload = mode == XDP_MODE_HW; enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB ? XDP_MODE_DRV : XDP_MODE_SKB; - if (!offload && dev_xdp_prog_id(dev, other_mode)) { + if (!offload && dev_xdp_prog(dev, other_mode)) { NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time"); return -EEXIST; } - - if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) { - NL_SET_ERR_MSG(extack, "XDP program already attached"); - return -EBUSY; - } - - prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP, - bpf_op == ops->ndo_bpf); - if (IS_ERR(prog)) - return PTR_ERR(prog); - - if (!offload && bpf_prog_is_dev_bound(prog->aux)) { + if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) { NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported"); - bpf_prog_put(prog); return -EINVAL; } - - if (prog->expected_attach_type == BPF_XDP_DEVMAP) { + if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) { NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device"); - bpf_prog_put(prog); return -EINVAL; } - - if (prog->expected_attach_type == BPF_XDP_CPUMAP) { - NL_SET_ERR_MSG(extack, - "BPF_XDP_CPUMAP programs can not be attached to a device"); - bpf_prog_put(prog); + if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) { + NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device"); return -EINVAL; } + } - /* prog->aux->id may be 0 for orphaned device-bound progs */ - if (prog->aux->id && prog->aux->id == prog_id) { - bpf_prog_put(prog); - return 0; + /* don't call drivers if the effective program didn't change */ + if (new_prog != cur_prog) { + bpf_op = dev_xdp_bpf_op(dev, mode); + if (!bpf_op) { + NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode"); + return -EOPNOTSUPP; } - } else { - if (!prog_id) - return 0; - prog = NULL; - } - err = dev_xdp_install(dev, mode, bpf_op, extack, flags, prog); - if (err < 0 && prog) { - bpf_prog_put(prog); - return err; + err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog); + if (err) + return err; } - dev_xdp_set_prog(dev, mode, prog); + + dev_xdp_set_prog(dev, mode, new_prog); + if (cur_prog) + bpf_prog_put(cur_prog); return 0; } /** + * dev_change_xdp_fd - set or clear a bpf program for a device rx path + * @dev: device + * @extack: netlink extended ack + * @fd: new program fd or negative value to clear + * @expected_fd: old program fd that userspace expects to replace or clear + * @flags: xdp-related flags + * + * Set or clear a bpf program for a device + */ +int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, + int fd, int expected_fd, u32 flags) +{ + enum bpf_xdp_mode mode = dev_xdp_mode(flags); + struct bpf_prog *new_prog = NULL, *old_prog = NULL; + int err; + + ASSERT_RTNL(); + + if (fd >= 0) { + new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP, + mode != XDP_MODE_SKB); + if (IS_ERR(new_prog)) + return PTR_ERR(new_prog); + } + + if (expected_fd >= 0) { + old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP, + mode != XDP_MODE_SKB); + if (IS_ERR(old_prog)) { + err = PTR_ERR(old_prog); + old_prog = NULL; + goto err_out; + } + } + + err = dev_xdp_attach(dev, extack, new_prog, old_prog, flags); + +err_out: + if (err && new_prog) + bpf_prog_put(new_prog); + if (old_prog) + bpf_prog_put(old_prog); + return err; +} + +/** * dev_new_index - allocate an ifindex * @net: the applicable net namespace * |